Ventilation Setup

Your chimney design is a vital part of a successful roaster installation. It impacts safety, efficiency, compliance, and even your community relationships. A well-planned ventilation system can make or break your business. Below, we outline key considerations to guide your design and installation process.

Key Considerations

General Design

• Two Separate Exhaust Pipes:
  • Cooling Pipe:
    • Carries a small amount of smoke and rarely needs cleaning.
    • Can exit the building close to the ground unless there are tables or foot traffic nearby.
    • Emits some fan noise, especially if the pipe is short.
    • Does not typically get very hot, though some heat is expected during the cooling phase.
  • Roasting Pipe:
    • Vents smoke and heat from the roasting process. This pipe can reach temperatures up to 150°C, so take care when passing through flammable materials like ceilings.
    • Requires the most maintenance as it poses the highest fire risk and is prone to blockages.

• Smoke Considerations:

  • Smoke is generated by the beans, not the machine. Larger machines produce more smoke (e.g., a 30kg roaster generates five times the smoke of a 6kg machine).
  • Plan your site to avoid venting smoke into neighboring living or working spaces.

• Local Regulations:

  • Check local air pollution laws, especially if your site is outside a commercial or industrial zone.
  • Practical considerations like avoiding complaints from neighbors are often more immediate concerns.

• Technical Documentation:

  • Refer to your roaster’s technical documentation for fan connections, outlet dimensions, and specifications.

• Consult Professionals:

  • Work with an HVAC professional to plan and install your system. While Genio provides general advice, local regulations and site-specific details require professional expertise.

• Recommendations:

  • Address potential concerns proactively. Engage your community and use this as a marketing tool to build goodwill.
  • Consider an afterburner solution only if complaints arise to save on unnecessary startup costs.

The Role of HVAC Professionals

We strongly recommend hiring an HVAC professional to design and install your chimney system. Their expertise ensures compliance with local regulations and safety standards while optimizing performance. HVAC professionals can:

• Plan the system layout based on your roaster's requirements and site conditions.
• Specify and source the correct materials, including pipe sizes and insulation.
• Ensure proper installation and testing for long-term reliability.

While Genio can provide general advice, HVAC professionals are critical for addressing specific installation needs and local regulations.

Maintenance and Safety

• Insulated Piping:

  • Keeps oils in a gaseous state, reducing maintenance and fire risks.
  • Often made of polished stainless steel, adding to your roastery’s aesthetic.
  • Costs more but is a worthwhile investment for safety and efficiency.

• Inspection Hatches:

  • Install a Y-piece with a removable cap at the stack's base for easier cleaning and as a drainage point for water.

• Regular Chimney Sweeping:

  • Schedule inspections and cleaning based on your roasting frequency, roaster size, pipe diameter, and roast degree.
  • Consult your HVAC installer for recommendations on reliable chimney sweeps.

• Fire Risk:

  • Oils from roasting beans condense on chimney walls and can ignite. Regular cleaning is the only way to prevent chimney fires.

• Blockage Risk:

  • Blocked chimneys are the most common issue. As smoke cools toward the chimney exit, oils, chaff, and debris build up, reducing the pipe diameter until it eventually blocks.
  • Regularly inspect the chimney exit for buildup—looking into the pipe from below is insufficient. Blockages increase fire risk and reduce roaster performance.

• Rain Covers:

  • Prevents rain, wind, birds, and rodents from entering. Opt for designs that swivel to reduce back pressure. Regular cleaning is essential.

Performance Factors

• Back Pressure:

  • Caused by blockages, bends, horizontal sections, or poorly designed rain covers.
  • Symptoms include chaff in the drawer or sparks exiting the drum.
  • Inspect and address promptly to avoid reduced performance or fire hazards.

• Draft:

  • Vertical pipes naturally create suction, improving airflow. Insulated pipes are critical in colder climates to maintain this draft and prevent back pressure.

• Bends and Length:

  • Limit 90-degree bends to avoid adding equivalent chimney length. Each bend adds ~3 meters to the overall resistance.
  • Keep total chimney length under 20 meters, with no more than 2 elbow joints.

• Horizontal Sections:

  • Limit to 5 meters or less. These areas are prone to buildup and require regular cleaning.

• Diameter:

  • Use appropriately sized pipes:
    • 125-160mm for 3-15kg roasters.
    • 160-200mm for larger machines.
  • Oversized pipes may cause poor draft and back pressure, while undersized pipes hinder performance.

Additional Features

• Spark Arrestors:

  • Essential for thatched-roof buildings or high fire-risk areas. Consult your HVAC professional.

• Modular Pipes:

  • A modular system with clamp-locked sections is easier to clean and modify.

• Height Above Roof:

  • Extend the chimney above the highest roof point to prevent downdrafts. Support cables may be necessary for tall chimneys.

• Flexible Piping:

  • Genio roasters typically include 5m of semi-rigid aluminum piping for connecting to a fixed stack.
  • Stainless steel semi-rigid pipes are recommended for durability.
  • Avoid soft aluminum pipes from hardware stores.

Additional Considerations

• Booster Fans:

  • Booster fans are rarely needed as roaster fans typically generate sufficient airflow.
  • If required (e.g., for very long or tall stacks), install the booster fan with a low-angle Y-joint into the main stack. Avoid inline connections, as they clog easily.

• Chimney Outlets:

  • Never install a grid at the chimney outlet. Ask your installer to confirm in writing that no grid has been installed. Grids are a common mistake and pose significant risks.

• Rain Covers:

  • Install a rain cover to protect against rain, wind, birds, and rodents.

Chimney Integration

• Kitchen Vent Systems:

  • It’s generally possible to connect your roaster’s chimney to an existing industrial kitchen system. Consult your HVAC professional.

• Pipe Joints:

  • Never join chimney pipes without professional oversight. Incorrect joins can cause back pressure and severe fire hazards.

Summary

A well-designed ventilation system ensures optimal performance, safety, and compliance while reducing maintenance and fire risks. From insulated piping and regular cleaning to proper draft management and chimney height, each aspect plays a crucial role. Consult an HVAC professional to ensure your system meets all technical and regulatory requirements. For more guidance, reach out to Genio Roasters.